Free AI tool
Content Similarity Checker
Check how similar two pieces of content are — detect duplicate content, plagiarism, or compare competitors. Free.
How it works
Each piece of content is turned into a vector by an embeddings model running on Cloudflare Workers AI, and the two vectors are compared with cosine similarity. The percentage is how closely they point in the same direction: 100% means the model reads them as the same content, 0% means it reads them as unrelated. The model is multilingual, so a comparison of two non-English pages works the same way.
A high score is a signal, not a verdict. Two pages can legitimately cover the same topic with the same vocabulary and still be worth publishing, while a paraphrased copy can score lower than the overlap deserves because the wording changed. Use the shared keywords to see what the two documents have in common, and read the verdict as a starting point rather than a ruling.
For search engines, near-duplicate pages compete with each other for the same query and split the signals between them. When that happens on your own site, the fix is usually a canonical tag or a rewrite rather than a new page. To measure a single page properly, run the free SEO audit.